DE102018108472A1 - Photovoltaic power generation plant, supply line for a power plant, mating plug and inverter - Google Patents

Abstract

A photovoltaic power generation plant (1) comprising a string (20) comprising a series connection of solar modules (10) electrically connected to an inverter (30) via connecting leads (50) for converting and feeding electrical power to the string (20) , is characterized in that the inverter (30) is adapted to provide an alternative operating power in the event that a normal operating power is obtainable neither from the mains nor from the entire string (20), only from one of the solar modules (10) Respectively. A supply line may supply the alternative operating power to the inverter (30). Furthermore, plugs (90) and mating plugs (100) of such a supply line are described, which can also be installed with an inverter (30).

Description

The invention relates to a photovoltaic power generation plant. Furthermore, the invention relates to a supply line for a photovoltaic power generation plant, a mating connector to a plug of the supply line, and an inverter.

Photovoltaics is one of the key technologies in the energy transition, ie the shift away from fossil fuels towards renewable energy sources. In this case, sunlight in a photovoltaic power generation plant is directly converted by means of solar modules of a solar generator into electrical power in the form of a DC voltage, which in turn is converted by means of an inverter into AC voltage for feeding into an AC voltage network. The resulting problem of electrical supply to the electronics of the inverter is typically solved by the inverter preferably takes the supply power from the AC mains, or, if the inverter is disconnected from the grid, from the connected solar generator. However, since the voltage of the irradiated solar generator is much higher than the voltage required for the supply, a lossy reduction of the solar generator voltage to the supply voltage must take place. In addition, there are requirements for operating states of the power generation plant, where in addition to the grid and the solar generator must be disconnected from the inverter or even the individual solar modules of the solar generator must be separated and / or shorted, so that voltage limits within the power generation plant for reasons of safety are not exceeded. Here eliminates the possibility of supply from the solar generator.

The font EP 2 267 860 A2 Therefore proposes to use an additional power source to supply an inverter with separate connection to the grid and the solar generator, which supplies the inverter with power from the grid.

It is in the light of the above-mentioned prior art object of this invention to show a photovoltaic power generation plant, in which the inverter can be supplied with electrical power even if the inverter is disconnected from the grid and, for example due to normative requirements tight voltage limits by the solar generator must be complied with. It is a further object of this invention to provide a connection line or a plug system with which a photovoltaic power generation plant is enabled to supply itself from a voltage-limited solar generator.

This object is achieved by a photovoltaic power generation plant having the features of claim 1, a supply line having the features of claim 13, and a plug having the features of claim 14. Preferred embodiments of the invention are described in the dependent claims.

A photovoltaic power generation plant according to the invention comprising a string comprising a series connection of solar modules, which is electrically connected to an inverter via connecting lines for converting and feeding the string's electrical power into a network, is characterized in that the inverter is adapted to provide an alternative operating power in the network Case that a normal operating power can not be obtained from the network or the entire string, only from one of the solar modules. The one of the solar modules that generates the alternative operating power is preferably placed at one end of the series circuit.

In a first embodiment, the alternative operating power is obtained from a voltage applied between solar module connections of the one solar module. In this case, all the power generated by the solar module is available as an alternative operating power.

In a second embodiment, one of the solar modules has a submodule connection, which is electrically connected to an intermediate point between submodules of the one solar module, wherein the alternative operating power is obtained from a voltage applied between the submodule connection and a solar module connection of the one solar module. As a result, only a part of the electric power that can be generated by the solar module is available as an alternative operating power, but due to the lower voltage, this power can be used more easily as an alternative operating power.

In a further embodiment, which can be combined with the first and second embodiment, a DC / DC converter, in particular an output voltage-controlled buck converter, for converting the alternative operating power is arranged between the one solar module and the inverter. The DC / DC converter converts the voltage provided by the solar module into a lower voltage value directly usable by inverters as an alternative operating power. If an operating voltage required by the inverter is higher than the voltage provided by the solar module, however, a step-up converter can also be used become. Likewise, of course, a high-buck converter can be used, which allows both an increase and a reduction of the solar module voltage.

The DC / DC converter is also preferably powered by the power provided by the solar module and advantageously operated only when the alternative operating power is required to operate the inverter.

In a particularly simple variant of a power generation plant according to the invention, the inverter is set up to accommodate the alternative operating power via the connecting lines. In this case, a blocking diode is arranged in a connecting line between the one of the solar modules and one of the connecting lines. If the string voltage applied between the connection lines is greater than the voltage of one of the solar modules, the blocking diode blocks and only allows a current flow if the string voltage falls below the voltage of the solar module, for example if a connection between the solar modules is disconnected.

The DC / DC converter or the blocking diode can be placed as separate components of the power generation plant in the vicinity of the solar modules or can also be integrated into the inverter.

In a particularly advantageous implementation of the power generation plant according to the invention, the inverter has a further connection for receiving the alternative operating power together with a string connection, via which one of the connection lines is connected to the inverter. The further connection and the string connection of the inverter can be integrated in a common plug connection. If the inverter has this further connection, a connecting line is preferably provided for transmitting the alternative operating power, which is laid together with the connection lines connected to the string connection. This connection line and the connection line connected to the string connection advantageously form a common supply line with a common external insulation, which preferably has a plug with respectively separate plug contacts for the connection line and the connection line at both ends.

If the photovoltaic power generation plant is set up to electrically isolate all solar modules of the string from each other when disconnected from the grid and / or in case of danger, and / or short-circuit all solar modules of the string (except for a solar module that provides the alternative operating power), nevertheless an alternative operating power to supply the inverter from the one - not shorted - solar module can be obtained. This alternative operating power can then be used, for example, to take the power generation plant back into operation after the hazard has ended, or to enable data communication with the power generation plant at any time.

Another aspect of the invention relates to a supply line for a photovoltaic power generation plant having an inverter and a string connected thereto from a series connection of solar modules. The supply line in this case has a connecting line for transmitting a string current of the photovoltaic power generation plant to an inverter, a connecting line for transmitting an alternative operating power to the inverter, and an outer insulation surrounding the connecting line and the connecting line, and an insulation resistance to a string voltage of the photovoltaic Energy generating plant has. At both ends of the supply line respectively male and female executed plugs are arranged, each having a plug contact for the connecting line and a plug contact for the connecting line, wherein the connecting line and the connecting line are preferably isolated from each other with an insulation strength, which is less than the insulation resistance to the String voltage of the photovoltaic power generation plant is, and in particular corresponds to an insulation resistance to a solar module voltage, and wherein the plug at both ends of the supply line are preferably plug compatible with SunClix connections. Such SunClix compounds are e.g. available from the company Phoenix Contact and have established themselves especially within the DC cabling of photovoltaic systems. The plug contact for the connected load corresponds to the plug contact of a conventional plug, while the plug contact for the connecting line is arranged laterally with respect to a plug-in axis of the plug connection and is electrically connected to a corresponding mating plug contact of a mating plug during insertion together with the plug contact of the connecting lead. For the purpose of protection against contact, plug contact and mating plug contact can each be accommodated in housing attachments made of insulating material. A transfer of the modification described above to other conventional in photovoltaic connection systems is conceivable and easy to implement.

A mating connector to a plug of such a supply line is the subject of Invention, wherein each plug contact of the plug is associated with a mating plug contact of the mating connector.

Such a mating connector may be used instead of a conventional plug-compatible mating connector as part of an inverter for establishing an electrical connection to a solar module in a photovoltaic power generation plant. In particular, the mating connector can be permanently installed in a housing opening of the inverter. In this way, a supply of the inverter can be made possible with an alternative operating performance, but can also be dispensed with such a supply by a conventional plug is plugged into the mating connector according to the invention.

• 1 eine erste Ausführungsform einer erfindungsgemäßen Energieerzeugungsanlage,
• 2 eine zweite Ausführungsform einer erfindungsgemäßen Energieerzeugungsanlage,
• 3 eine dritte Ausführungsform einer erfindungsgemäßen Energieerzeugungsanlage,
• 4 eine Ausgestaltung eines Solarmoduls zur Verwendung in einer erfindungsgemäßen Energieerzeugungsanlage,
• 5 eine Ausführung eines Steckers einer erfindungsgemäßen Versorgungsleitung, und
• 6 eine Ausführung eines zu dem Stecker der 5 als Gegensteckerausgebildeten Steckers zeigen.

In the following the invention will be described in more detail with reference to figures, of which

• 1 A first embodiment of a power generation plant according to the invention,
• 2 A second embodiment of a power generation plant according to the invention,
• 3 A third embodiment of a power generation plant according to the invention,
• 4 An embodiment of a solar module for use in a power generation plant according to the invention,
• 5 an embodiment of a plug of a supply line according to the invention, and
• 6 an embodiment of the plug to the 5 show as mating connector designed plug.

A power generation plant according to the invention 1 has an inverter 30 on that via a network connection 40 can be connected to an AC voltage network. DC side is the inverter 30 via connecting cables 50 with a string 20 trained solar generator electrically connected. The connecting cables 50 are with string connections 51 . 52 of the inverter 30 connected. The string 20 is through a series connection of solar modules 10 educated. One of the solar modules 10 is with a first solar module connection to one of the supply line 50 connected and with a second solar module connection to a connecting line 60 , as well as with other solar modules. The connection line 60 is via a supply connection 61 with the inverter 30 connected so that the inverter 30 Optionally, both an electrical power of the entire string 20 over the string connections 51 . 52 can receive as well as an alternative operating power, only through the one of the solar modules 10 is generated via one of the string connectors 51 and the supply connection 61 , For the provision of the alternative operating performance, it is not decisive whether this is one of the solar modules 10 with the other solar modules of the string 20 is electrically connected or whether the other solar modules generate energy at all. The connecting line is preferred 60 together with one of the connecting cables 50 laid and both together form a supply line with common external insulation. The isolation requirement of the trunk 60 opposite the one connecting cable 50 does not require elaborate insulation, since the voltage between the two lines by the voltage of the solar module 10 is determined and thus, for example, too small to form an arc.

Another embodiment of a photovoltaic power generation plant according to the invention 1 is in 2 shown. Here, instead of an additional connection line only an additional connection between the one of the solar modules 10 , one-sided with a connecting cable 50 with the inverters 30 is provided, wherein the additional connection via a diode 70 with the other supply line 50 he follows. This ensures that the inverter 30 over his string connections 51 . 52 at least one of the one of the solar modules 10 of the string 20 generated power can receive, even if the other solar modules can not provide power over the supply lines, for example, because they are short-circuited or electrically isolated from each other. On the other hand, the diode prevents 70 a current flow through this connection when connected to the supply lines 50 fitting tension of the string 20 the voltage of one solar module 10 exceeds.

The further embodiment of the 3 differs from the embodiment of the 2 in that instead of a diode 70 now a DC / DC converter 80 is used. This can be designed as a boost converter or as a buck converter. The DC / DC converter 80 is preferably only operated when the string 20 over the connection lines 50 does not provide any service. By the operation of the DC / DC converter 80 in this case the inverter 30 an alternative operating power over the string connections 51 . 52 fed. In an advantageous embodiment of the DC / DC converter is operated as output voltage controlled converter, particularly preferred is the DC / DC converter 80 a buck converter, the alternative operating power at a given operating voltage, for example, 5 V or 12 V, from the voltage of a solar module 10 generates and provides. The supply power for the operation of the DC / DC converter 80 in this case is preferably also the one solar module 10 taken.

4 schematically shows how a power plant 1 can be constructed using connectors so that they can implement the inventive teaching, but at the same time largely corresponds to a conventional power generation plant. A solar module 10 is in 3 submodules 11 each with parallel-connected bypass diodes divided between two solar module connections 12 are arranged. In addition, the solar module points 10 a supply connection 13 on that with a connection point between 2 submodules 11 connected is. The solar module connections 12 , as well as the supply connection 13 can in a junction box of the solar module 10 be housed. In the case shown are other solar modules 10 , who share a string 20 form, for the sake of simplicity only represented by a single module.

The solar module 10 is at a solar module connection 12 via a first connecting cable 50 and conventional SunClix connectors with a string connector 52 of the inverter 30 connected. At the second solar module connection 12 is a second connection line 50 connected, in common with a connecting line 60 connected to the supply connection 13 connected to a modified connector 90 is guided. The modified plug 90 will be in contact with 5 described in detail and is in plug connection with a modified mating connector 100 who is in contact with 6 will be described in more detail. From the modified mating connector 100 starting from the connecting line 50 and the connection line 60 within a common external insulation 110 to another modified connector 90 so that this connection is a supply line for the power generation plant 1 forms. The further modified plug 90 is then over another modified mating connector 100 with a supply connection 61 , as well as a string connection 51 of the inverter 30 connected. In this way, that of the corresponding submodules 11 of the solar module 10 generated power over the connections 12 . 13 , the wires 50 . 60 , as well as the connector via the modified connector 90 and the modified mating connectors 100 at the connections 51 . 61 provided and can be used as an alternative operating power from the inverter 30 be used. The string connection 51 and the supply connection 61 can be considered as the case of the inverter 30 fixed mating connector analogous to the modified mating connector 100 be executed (not shown). In this case, the modified plug shown 90 with the inverter 30 be connected via a supply line, in which the connecting line 60 and the connection line 50 each at one end with a modified connector 90 and at the other end with a modified mating connector 100 are provided.

5 shows more details of a modified connector 90 , in which 5a the modified connector 90 in a front view and 5b the modified connector 90 show in a side view. The modified plug 90 includes a housing whose geometric dimensions correspond to the geometrical dimensions of a conventional SunClix connector. Also a central contact structure 55 that with a connection cable 50 is connectable and designed to transfer the entire string current of a solar generator, corresponds to the contact structure of a conventional SunClix connector. In addition, the modified connector 90 a lateral attachment of insulating material with a further contact structure 65 on that with the connection line 60 is connectable. The further contact structure 65 can be designed as a contact pin, and the attachment is preferably designed such that the contact structure 65 is arranged finger-safe inside the essay.

6 shows more details of a modified mating connector 100 , in which 6a the modified mating connector 100 in a front view and 6b the modified mating connector 100 show in a side view. The modified mating connector 100 includes a housing whose geometrical dimensions correspond to the geometrical dimensions of a conventional SunClix mating connector. Also a central contact structure 55 that with a connection cable 50 is connectable and designed to transfer the entire string current of a solar generator, corresponds to the contact structure of a conventional SunClix mating connector. In addition, the modified mating connector 100 a lateral attachment of insulating material with a further contact structure 65 on that with the connection line 60 is connectable. The further contact structure 65 may be designed as a contact sleeve, and the attachment is preferably designed such that the contact structure 65 is arranged finger-safe inside the essay. Furthermore, the attachment of the modified mating connector 100 designed so that it is in a modified connector 90 according to 5 can be inserted, and thereby both the contact structures 55 as well as the contact structures 65 of the modified plug 90 with the contact structures 55 and the contact structures 65 of the modified mating connector 100 be electrically connected. The contact structures 55 . 65 be protected from contamination nestled by the nested housings or attachments of the plug and the mating connector, for example by the essays are inserted into each other.

Due to the lateral arrangement of the essay both the modified connector 90 as well as the modified mating connector 100 still in conventional SunClix plugs or mating plug are plugged. In this way it can be achieved that a conventional power generation plant can be converted by replacing the SunClix plug and a little cabling in a power generation plant according to the invention. In this case, exposed plug contacts, which arise by inserting conventional SunClix plug into plug or mating plug according to the invention, can be protected from soiling and corrosion by sealing caps.

LIST OF REFERENCE NUMBERS

1

Power generation plant

10

solar module

11

sub-module

12

Solar module connector

13

supply terminal

20

string

30

inverter

40

mains connection

50

connecting cable

51

string connection

52

string connection

55

Contact structure

60

connecting line

61

supply terminal

65

Contact structure

70

diode

80

DC / DC converter

90

plug

100

Mating connector

110

exterior insulation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2267860 A2 [0003]

Claims (15)

A photovoltaic power generation plant (1) comprising a string (20) comprising a series connection of solar modules (10) electrically connected to an inverter (30) via connection lines (50) for converting and feeding electrical power of the string (20) into a network, characterized in that the inverter (30) is adapted to receive an alternative operating power only from one of the solar modules (10) in the event that a normal operating power is neither obtainable from the network nor from the entire string (20). Photovoltaic power generation plant (1) according to Claim 1 wherein the one of the solar modules (10) is placed at one end of the series connection. Photovoltaic power generation plant (1) according to one of the preceding claims, wherein the one of the solar modules (10) has a sub-module connection (13) which is electrically connected to an intermediate point between sub-modules (11) of the one solar module (10), wherein the alternative operating power a voltage applied between the submodule connection (13) and a solar module connection (12) of the one solar module (10) is obtained. Photovoltaic power generation plant (1) according to Claim 1 or 2 wherein the alternative operating power is obtained from a voltage applied between solar module terminals (12) of the one solar module (10). Photovoltaic power generation plant (1) according to one of the preceding claims, wherein between the one solar module (10) and the inverter (30), a DC / DC converter (80), in particular an output voltage controlled buck converter, is arranged to convert the alternative operating power. A photovoltaic power plant (1) according to any one of the preceding claims, wherein the inverter (30) is adapted to receive the alternative operating power via the leads (50), and wherein a blocking diode (70) is provided in a connecting lead (60) between the one of the solar modules (70). 10) and one of the connection lines (50) is arranged. Photovoltaic power generation plant (1) according to Claim 5 or 6 , wherein the DC / DC converter (80) and the blocking diode (70) are integrated in the inverter (30). Photovoltaic power generation plant (1) according to one of the preceding claims, wherein the inverter (30) has a further terminal (61) for receiving the alternative operating power together with a string terminal (51) via which one of the connection lines (50) to the inverter (30 ) connected is. Photovoltaic power generation plant (1) according to Claim 8 , wherein the further connection (61) and the string connection (51) of the inverter are integrated in a common socket. Photovoltaic power generation plant (1) according to Claim 8 or 9 wherein a connecting line (60) is provided for transmitting the alternative operating power, which is laid in common with the connecting lines (50) connected to the string terminal (51). Photovoltaic power generation plant (1) according to Claim 10 in that the connecting line (60) and the connection line (50) connected to the string connection (51) form a common supply line with a common external insulation, which at each end has a plug (90) with respective plug contacts for the connecting line (60) and the Connecting line (50). Photovoltaic power generation plant (1) according to any one of the preceding claims, wherein the power generation plant (1) is adapted to electrically disconnect from each other and / or all solar modules when disconnected from the grid and / or in case of danger all solar modules (10) of the string (20) short to one solar module (10) of the string (20). Supply line for a photovoltaic power generation plant (1) with an inverter (30) and a string connected thereto (20) from a series connection of solar modules (10), comprising: - a connecting line (50) for transmitting a string current of the photovoltaic power generation plant (1) the inverter (30), - a connecting line (60) for transmitting an alternative operating power to the inverter (30), - an outer insulation (110) surrounding the connecting line (50) and the connecting line (60) and having an insulation resistance a string voltage of the photovoltaic power generation plant (1), and - each having a male or female connector (90) at each of the two ends of the supply line, each having a plug contact for the connecting line (50) and a plug contact for the connecting line (60) wherein the connecting line (50) and the connecting line (60) with an insulation resistance isolated from each other, which is lower than the insulation strength against the string voltage of the photovoltaic power generation plant (1), in particular an insulation resistance to a solar module voltage corresponds, and wherein the plug at both ends of the supply line are plug compatible with SunClix connections. Mating connector (100) to one of the plugs (90) of a supply line to Claim 13 , wherein each plug contact of one of the plug (90) is associated with a mating plug contact. An inverter (30) for use in a photovoltaic power plant (1), comprising a mating connector (100) Claim 14 for producing an electrical connection with a solar module (10) of the power generation plant (1).

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